Soft Robot Challenge

Tufts University student teams participated in the RoboSoft Grand Challenge as part of Soft Robotics Week held on April 25-30, 2016 in Livorno, Italy. The RoboSoft Grand Challenge encompasses two different competitions: a race to avoid obstacles on different terrains and a competition to manipulate different objects. Tufts undergraduate and graduate students involved in the Soft Material Robotics (SMR) IGERT program will send three different robots to compete in this year’s events.

Terrestrial Race Challenge: SLABot

The SLABot buckles into a folded configuration when one of the motor-tendons is actuated.

The Soft Locomotive Autonomous Robot (SLABot) is an experiment in the design of locomotion-capable soft bodied robots. The goal is to discover the simplest geometry and actuator arrangement that will produce complex behavior for movement through unstructured environments. SLABot is constructed of a 150x300x10mm slab of cast polyurethane foam. Motor-tendon actuators are arranged in a specific orientation to produce forward locomotion and steering. The tendons are laced through the foam slab and, when contracted, compress and buckle the slab, revealing differential friction surfaces. Leveraging decoupled control of the bucking states and the highly deformable foam, the robot is capable of moving efficiently with any motor tendon arrangement.

Team leader

Vishesh Vikas, postdoctoral research scholar, Department of Biology

Team members

Eliad Cohen, plastics engineering, University of Massachusetts Lowell, affiliate of the Department of Biomedical Engineering

Terrestrial Race Challenge: TSRP

The TSRP robot is inspired by the tobacco hornworm, or Manduca sexta, a caterpillar that is a primary focus of Professor Barry Trimmer's lab. The body of the robot is made of several soft foam sections, much like a caterpillar body. The foam sections compress and expand to produce unique gaits similar to caterpillar motion. The foot of the robot, also inspired by the caterpillar, has an asymmetric friction mechanism. This means the force due to the friction between the robot and its environment is greater in one direction. The combined action of body expansion and directional friction produces forward motion.

The novel aspect of this robot is its means of actuation. Typically, robots move using an active or actuated process. The TSRP robot uses the expansion of the foam body, which is a passive recovery process, to provide outward force. Since this process is passive, the robot can easily deform around features in its environment and can leverage this ability to move more effectively in many situations where traditional robots would struggle.

Manipulation Challenge: Tele-operable In-Home Robotic Assistant

The Tele-operable In-Home Robotic Assistant (TIHRA) is designed to help quadriplegics gain more autonomy in their daily lives. TIHRA is a robotic arm with four degrees of freedom (two in the shoulder, one in the elbow, and one in the wrist) and a robotic manipulator composed of both hard and soft parts, which make TIHRA inherently safe for use. The grippers on the manipulator are a novel interpretation of the Fin Ray Effect and almost entirely soft. TIHRA's manipulator is tendon driven: a tendon in the palm is pulled by a DC motor, causing the grippers to close and conform around an object. Currently, TIHRA is capable of picking up objects under two pounds, but the team would is working to increase that to five pounds.